January 10 – WWII: Mechelen incident: A German plane carrying secret plans for the invasion of western Europe makes a forced landing in Belgium, leading to mobilization of defense forces in the Low Countries.

Women's stockings made of nylon are first placed on sale across the United States. Almost five million pairs are bought on this day.[2]

May 16 – President of the United States Franklin D. Roosevelt, addressing a joint session of the U.S. Congress, asks for an extraordinary credit of approximately $900 million to finance construction of at least 50,000 airplanes per year.

July 14 – WWII: Winston Churchill, in a worldwide broadcast, proclaims the intention of Great Britain to fight alone against Germany whatever the outcome: "We shall seek no terms. We shall tolerate no parley. We may show mercy. We shall ask none."

WWII: "The Hardest Day" in the Battle of Britain: both sides lose more aircraft combined on this day than at any other point during the campaign without the Luftwaffe achieving dominance over RAF Fighter Command.

September 2 – WWII: Destroyers for Bases Agreement between United States and Great Britain is announced to the effect that 50 U.S. destroyers needed for escort work will be transferred to Great Britain. In return, United States gains 99-year leases on British bases in the North Atlantic, West Indies and Bermuda.

September 22 – Japan enters French Indochina: an agreement is signed in which Japan promises to station no more than 6,000 troops there, and never have more than 25,000 transiting the colony. Rights were also given for three airfields.

September 26 – A group of Japanese officers in violation of an agreement signed four days earlier with French Indochina, take Đồng Đăng and Lam Sơn with 40 Franco-Vietnamese troops killed and around 1,000 deserting. The same day the United States imposes a total embargo on all scrap metal shipments to Japan.

November 13 – Walt Disney's Fantasia is released. It is the first box office failure for Disney, though it eventually recoups its cost years later, and becomes one of the most highly regarded of Disney's films.

November 14 – WWII: The city centre of Coventry, England is destroyed by 500 Luftwaffe bombers: 150,000 fire bombs, 503 tons of high explosives, and 130 parachute mines level 60,000 of the city's 75,000 buildings; 568 people are killed, during the Coventry Blitz.

December 17 – President Roosevelt, at his regular press conference, first sets forth the outline of his plan to send aid to Great Britain that will become known as Lend-Lease.

December 23 – WWII: Winston Churchill, in a broadcast address to the people of Italy, blames Benito Mussolini for leading his nation to war against the British, contrary to Italy's historic friendship with them: "One man has arrayed the trustees and inheritors of ancient Rome upon the side of the ferocious pagan barbarians."

December 24 – Mahatma Gandhi, Indian spiritual non-violence leader writes his second letter to Adolf Hitler addressing him "My friend", requesting him to stop the war Germany had begun.